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UNITED STATES PATENT Ca rion,

ERIC A. STARKE, OF SAN RAFAEL, CALIFORNIA.

PROCESS OF PURIFYING AND REFINING CALIFORNIA PETROLEUM-OILS.

SPECIFICATION forming part of Letters Patent No. 597,920, dated January25, 1898.

Application filed August 31, 1896. Serial No. 604,484 (No specimens) Toall whom it may concern:

Be it known that 1, Euro A. STARKE, a citizen of the United States,residing at San Rafael, county of Marin, State of California, haveinvented an Improvement in the Processes of Purification and Refining ofCalifornia Petroleum -Oils for Illuminating Purposes; and I herebydeclare the following to be a full, clear, and exact description of thesame.

My invention relates to a new process of purifying and refiningCalifornia petroleumoils for illuminating purposes, in which I firstremove from said oils the less refractory bodies contained therein bytreatingsaid oils with concentrated caustic lye or sulfuric acid.

and in which I secondly remove from the resulting mass the morerefractory bodies by treating said resulting mass with sulfuric anhydridor such solution of sulfuric anhydrid, as is hereinafter moreparticularly described.

My invention is particularly applicable to and particularly concernsthat class of petroleum-oils which on account of certain distinctivepeculiarities has come to be known commercially and otherwise by thedescriptive term of California oils.

The term California oils is not used in the geographical sense or tosignify geographical limitation to the State of California alone. On thecontrary, it is used to designate a certain allied species or class ofpetroleum-oils occurring in the State of California and also to someextent in the States and Territories bordering upon or adjacent to thePacific coast of the United States, which oils, by reason of theircontaining and being saturated with an excessive quantity of refractorybodies and matters of a carbonaceous nature, have hitherto resisted allefforts and attempts to make, manufacture, or in any way producetherefrom an illuminating-oil that would burn in any form of lamp orburner hitherto invented or known to the trade without giving off unduesmoke and without emitting noxious vapors in undue quantities. Theserefractory bodies and matters of a carbonaceous nature so present inthese California oils have constantly tended to clog and have cloggedfrom time to time the wicks of any and of all kinds of lamps andburners, and

the said refractory bodies and matters of a carbonaceous nature. 1

All methods and processes heretofore known and used in the treatment,purification, and refining of the said California petroleum-oils, so asto produce from them illuminating-oils, have been carried out by meansof a treatment with sulfuric acid of about 66 Baum at temperaturesvarying from 60 Fahrenheit to 250 Fahrenheit. The said methods andprocesses heretofore known and used in the treatment, purifying, andrefining of California petroleum-oils have never been successful inproducing from them an illuminatingoil that Would burn without unduesmoke and without emitting noxious vapors in excessive quantities orthat could be sold by itself as an illuminating-oil in the regular andordinary course of trade or commerce. So. refractory have been thesebodies and matters of a carbonaceous nature in these California oilsthat it has been necessary in the production and refining ofilluminating-oils from them to resort to three or four separate andsuccessive distillations of the same batches of oil accompanying and aspart of the treatment with said sulfuric acid, thereby entailing largeoutlays and expenses in labor, fuel, loss of time, wear and tear ofplant, and diminution by losses arising from successive distillations inpercentages of illuminating-oils obtained.

In my invention and process I have overcome these difficulties by,first, removing the less refractory bodies contained in the Californiapetroleum-oils or their distillates by treating the same withconcentrated caustic lye or sulfuric acid, and, secondly, and as part ofthe same invention and process by treatment of the resulting mass withsulfuric anhydrid or such solutions of sulfuric auhydrid as arehereinafter described.

In the application of my invention and process I proceed substantiallyas follows: I first IOO subject the crude oil to a single distillation,thereby eliminating from it the heavier and non-volatile tarry matters.I then mix with the resultant distillate from five to twenty per cent.,by weight, of the ordinary sulfuric acid of about 66 Baum, or from tento twenty-five per cent., by weight, of concentrated soda-lye or othercaustic lye of about 45 Baum, and heat the mass While so mixed to atemperature of about 160 Fahrenheit when sulfuric acid is employed; butin order to facilitate the reaction a temperature exceeding 200Fahrenheit is preferable when soda-lye or other caustic lye is employed,and I agitate the mass all the 'while with an airblast or othermechanical means for about an -hour7s time, @e length of the time ofagita tion dependingon the density of the distillate. The higher thespecific gravity of the said distillate the greater would bethepercentage of the said acid or of the said caustic lyes that I would useand also the longer the time I would allow for the agitation. After thecompletion of this first agitation with ordinary sulfuric acid or withcaustic lye, as aforesaid, (and by which treatment all of the lessrefractory matters are removed, leaving only those of a more stablecombination in the said resulting mass,) the said resulting mass isallowed to rest and the tarry residuum (or sludge) is drawn off. Therehas now been eliminated from the oil all refractory bodies and mattersof a carbonaceous nature that are in any way or at all susceptible ofelimination by any form or method of treatment with ordinary sulfuricacid or by any form or method of treatment with any alkaline substances;but there are still left in the oil certain other and still morerefractory bodies and matters of a carbonaceous nature that cannot betaken away or eliminated in any way or at all by any form or strength ofordinary sulfuric acid, or by any method or kind of treatment therewith,or by any method or kind of treatment with any alkaline sub stances. Upto this point and at this stage of the process said oil could not besuccessfully burned in any form of lamp or burner hitherto invented orknown to the trade. It becomes now, therefore, necessary to use somefurther and more powerful agent that will act upon and eliminate thisclass of still more refractory bodies and matters. For this purpose Inow use and subject the oil to treatment with sulfuric anhydrid orsolutions thereof,

as are hereinafter described.

The amount of sulfuric anhydrid ($0,) I employ depends wholly on thedensity of the distillate to be purified and also on the purity of theoriginal petroleum.

WVhen distillates of about 45 Baum are to be treated, five per cent. ofsulfuric anhydrid (S0 is generally sufiicient to purify the oil 3 butthe oil from some wells requires much more, often as much as fifteen percent. WVhen a distillate of greater gravity is to be refined, more ofthe S0 is required, as it seems that the heavier oils contain more ofthe refractorybodies than the lighter.

WVhen the sulfuric anhydrid is added to a distillate, the reaction isvery violent, but of short duration, depending to some extent on thegravity of the oil employed and the form of the sulfuric anhydrid. Whena light-gravity oil is treated, the solid SO can be employed. When aheavier form of distillate is used, the solid form of sulfuric anhydridcannot be employed, as the crystals of the S0 are at once completelysurrounded with a coating of black tarry matter, which prevents anyfurther action. Therefore an admixture of some other matter is necessaryin order to prevent this coating. Sulfuric acid (H 80 as an admixturemaking fuming acid must then be employed, as it is the cheapest methodof diluting the SO Phosphoric acid is better than sulfuric acid as adiluent, and boric acid makes a solid form, which gives good results. Infact, almost any substance that will not make a stable compound with theS0 will answer the purpose of a diluent. The idea is to get it into theoil and prevent the coating of the crystals with tarry matter. When oncein the oil, sulfuric anhydrid seems to attack the refractory bodies,making a tarry mass. It also seems to split off from the molecules ofthe oil some of the carbon and hydrogen sufficient to make a lighthyrocarbon and then combine/ therewith, the resulting combination notbeing soluble in the oil. I have come to this conclusion from the factthat the fire testof oil thus treated is raised from 20 to 40Fahrenheit. This may possibly be explained also by the fact that lighthydrocarbon oils are held in solution by the petroleum and thatsulfuricanhydrid is capable of combining therewith. Be this as it may, ordinarysulfuric acid (H 80 is wholly incapable of effecting its removal. I thenagitate the mass, at the same time never allowing the temperature tofall below 80 Fahrenheit. all chemical activity has ceased, which ismade evident by the amount of heat required to be applied to the mass inorder to maintain the. temperature thereof above 80 Fahrenheit. Afterall chemical action has ceased the mass is allowed to rest and the blackand thick tarry residuev is drawn off, and the oil is then subjected tosuccessive washings with water and soda-lye or otheralkaline substancesin the ordinary way. The oil is now ready for use and is fully equal inquality and in illuminating power to the best grades and brands ofEastern water-white illuminating-oils and equally with them will burn inany form of lamp without giving Off smoke or emitting noxious vapors.

Bymy invention and process as above described there is accomplished forthe first time that which has never been accomplished or brought aboutby any other process or method of treatment hitherto invented, used, oremployed upon or in connection with the This agitation is continueduntil' said California oils-that is to say, the production from the saidCalifornia oils of "an illuminating-oil that will burn in any form oflamp or burner that has ever been invented or known to the trade withequal illuminating power and in all respects as Well as the best brandsof eastern water-White illuminating-oils.

Among the other advantages and improvements resulting from theapplication of my invention and process to the treatment of the saidCalifornia oils may be mentioned the following: First, the raising ofthe fire test of said oils; secondly, the ability to refine and producehigh grade illuminating-oils from and thereby to utilize Californiacrude petroleum of a higher specific gravity than has ever beensusceptible of successful treatment or refining by any other method orprocess hitherto employed; thirdly, the obtaining from said Californiacrude petroleum of apercentage pf high-grade illuminating-oil greatereven than the percentage of poor and inferior illuminating-oil hithertoobtain ed therefrom, and, fourthly, the accomplishing by onedistillation of what has never been accomplished with or in regard toCalifornia oils even when employing the three or fourdistillationshitherto always made use of in treating and refining saidoils, and from this result large economyand saving inlabor,fuel,tin1e,and general Wear and tear of plant andmachinery and inthe percentage of loss consequent upon and hitherto regularly ensuingfrom the repeated and successive distillations that have beennecessarily employed.

Having thus described my invention,what I claim as new, and desire tosecure by Letters Patent, is

1. The process herein described of treating, purifying and refiningCalifornia petroleum-oils, so as to produce from them illuminating-oilswhich process consists,essentially, in first removingthe less refractorysubstances by treating said oils with a solvent or menstruum and thentreating the resulting product vvith sulfuric anhydrid to remove themore refractory substances.

2. The improved process herein described of treating, purifying andrefining Califor nia petroleum-oils, so as to produce from themilluminating-oils, which consists, essentially,in first removing theless refractory bodies by treating said oils,with a solvent ormenstruuni in the presence of heat and then removing from the resultingmass the more refractory bodies by treating said mass with sulfuricanhydrid.

In witness whereof I have hereunto set my Witnesses Wu. F. Boo'rH,HOLLAND SMITH.

